System information:
  Fedora Core 1 with 2.6 kernel from Fedora Development and alsa stuff from
freshrpms.

Playback with osssink works fine (thought alsa emulation layer) and playing
the same file with alsaplayer also works fine

Pipeline:

  gst-launch filesrc location=natt_uggla.mp3 ! mad ! alsasink

Error output:

  pcm_plug.c:882: snd_pcm_plug_hw_params: Assertion `err >= 0' failed.

Traceback:
  

+ Trace 44802

$5 = {dl_handle = 0x0, name = 0x48 <Address 0x48 out of bounds>, type = 72,
  stream = SND_PCM_STREAM_PLAYBACK, mode = 65, poll_fd = 12094496,
  poll_events = 35872, setup = 12094440, access = 159056396,
  format = 12091960, subformat = 41, channels = 12094440, rate = 12094440,
  period_size = 12094440, period_time = 3, periods = {min = 0, max = 0,
    openmin = 0, openmax = 0, integer = 0, empty = 1}, tick_time = 156821544,
  tstamp_mode = 64, period_step = 4080, sleep_min = 156817016,
  avail_min = 156808720, start_threshold = 0, stop_threshold = 0,
  silence_threshold = 156812676, silence_size = 156812752, xfer_align = 32,
  boundary = 0, info = 156810268, msbits = 156812760, rate_num = 0,
  rate_den = 0, fifo_size = 156812984, buffer_size = 0, buffer_time = {
    min = 8, max = 156813008, openmin = 1, openmax = 1, integer = 0,
    empty = 0}, sample_bits = 0, frame_bits = 156813060, appl = {master = 0x0,
    ptr = 0x0, fd = 146423056, offset = 0, link_dst_count = 0, link_dst = 0x2,
    private_data = 0x958c718, changed = 0}, hw = {master = 0xffffffff,
    ptr = 0x8287600, fd = 1916880735, offset = 7954802,
    link_dst_count = 1635017060, link_dst = 0xb88b00, private_data = 0x6e656c,
    changed = 0}, min_align = 0, mmap_rw = 156812676, shadow_mmap = 156813068,
  donot_close = 32, mmap_channels = 0x0, running_areas = 0x958bc1c,
  stopped_areas = 0x958c714, ops = 0x0, fast_ops = 0x0, op_arg = 0x958c738,
  fast_op_arg = 0x0, private_data = 0x8, async_handlers = {next = 0x958c750,
    prev = 0x3}}